Automatic fluid actuated displacement pump



W. W. THAYER AUTOMATIC FLUID ACTUATED DISPLACEMENT PUMP March 1, 1938.

Filed Aug. 51, 1936 Q 2 Sheets-Sheet l ATTORNEY March 1 1938. w. w. THAYER AUTOMATIC FLUID ACTUATED DISPLACEMENT PUMP Filed Aug. 31, 1936 2 Sheets-Sheet 2 A D G J .2

'INVE TYOR. Z1): e/

/Zau @7 A TTORNEY.

Patented Mar. 1, 1938 uurrso s'mres PATENT OFFKCE AUTOMIATIC- FLUID ACTUATED DISPLACE- MENT PUMP cisco, Calif.-

Application August 31, 1936, Serial No. 98,673

8 Claims.

This invention relates to an automatic, fluid actuated, displacement pump. It is especially designed and adapted to elevate fluids, such as oil, from oil wells, and water from water wells. The pump operates on the displacement principle using compressed gas or air, as the case may be, for the lifting medium.

In the oil industry, many new problems are confronting theoperator and producer. Wells have reached great depths, owing to the discovcry of deeper oil sands. This fact alone presents many new problems and makes it necessary and imperative that some more efficient and economical method of lifting oil be developed.

The gas lift method of producing oil, which is based upon the old air lift principle, has been used rather extensively throughout the oil fields of the United States for a number of years past, but certain limitations as to its use exist, and under certain conditions it is proving to be an inefficient and expensive method of producing oil.

The most important limitations of the gas lift method, as generally employed, are the exces sively high gas-oil ratios and the tendency to form heavy emulsions in wells where oil is produced in association with water.

Other extremely important unfavorable factors relating to the gas lift method of producing oil, are the fact that an aerated or gasified col umn is produced, which emulsifies the oil to such an extent that special and expensive treatment is necessary, in order to separate the oil and water. Another and vitally important unfavorable factor is, that in producing oil by the gas lift method, the operating pressure is exerted against the oil formation, thereby holding back or preventing the oil from entering the Wells and thereby limiting the production.

All oil production equipment in use today in the oil fields is limited to the capacity of the equipment. For example, the ordinary suckerrod pump, commonly used in the oil fields, is limited to a few hundred barrels per day, While the well may have a capacity of several times this amount, but the equipment is not capable of bringing it to the surface.

operating pressure, whatever it may be, exerted against the formation, much of the oil is prevented from entering the Well, thereby again providing the same limitation of equipment.

The same limitations and unfavorable conditions exist as regards pumping equipment for the pumping of water for irrigation; the water tables in practically all irrigation sections of the The same situa- I, tion applies to the gas lift method, for with the country have been lowered to a point where the cost of lifting water is almost prohibitive with the present equipment and a more efficient and economical method of lifting water must therefore be made available.

The object of the present invention is generally to improve and simplify the construction and operation of fluid actuated displacement pumps of the character described; to provide a pump which employs only two valves, to-wit, a foot valve and a. gas valve, said valves being automatically operated by liquid and gas pressure, respectively, and being operated independently of each other; to provide a pump which permits increased production by elimination of back pressure on the formation, thereby giving more freedom for the entry of the oil into the well casing; to provide a'pump which materially reduces the gas-oil ratio by reducing the volume of gas; employed and by utilizing to a. greater extent the expanding force of the gas; to provide a pump which substantially eliminates aeration of the oil column and the formation of an emulsion where water is associated with the oil;, to provide a pump the output of which is limited only by the capacity of the well, that is, whichwill pump all the oil the well will make; and, further, to provide a pump which, if anything, will increase the ultimate yield of the well toward steady production .and materially decreases lift- 3 ing or pumping costs.

The pump is shown by way of illustration in the accompanying drawings, in which- Fig. 1 is a central, vertical, longitudinal section of the pump;

Fig; 2 is a cross section on line II--II of Fig. 1; 5'

Fig. 3 is a cross section on line III-411 of Fig. 1;

Fig. 4 is a. cross section on line IV-IV of Fig. 1;

Fig. 5 is a cross section on line V-V of Fig. l; and

Fig. 6 is a vertical, longitudinal section show: ing the complete pump installation in. a well.

Referring to the drawings in detail, and par ticularly Fig. 6, A indicates a standard form of well casing; B a casing head; and C the oil discharge column depending therefrom. Gas under pressure is delivered to the space D formed be tween the casing and the discharge column by either of the pipes E or F and enters the pump, generally indicated at G, through a perforated tube or screen H; a packer J being disposed below the pump to confine the gas and to prevent it from exerting any pressure on the formation from which the oil is derived.

The pump proper is best illustrated in Figs. 1

to 5, inclusive, and comprises a cylindrical-shaped elongated shell or casing 2, which is provided with an inlet 3 at its lower end and an outlet 4 at the upper end which connects with the discharge column C. An annular space 5 is formed around the outlet which is enclosed by the screen H and this space is connected through a duct 6 with -a valve housing i, having outlet ports 8 which will be open or closed by a plunger valve 9 hereinafter to be referred to .as the gas valve.

The lower end of the valve housing 7 terminates in a cage l0 having a seat ll provided for the reception of a foot valve l2. The gas valve is provided with an extension M which extends through the foot valve, this extension being longer than the foot valve and being provided with collars l5 and I6, which limits movement of the gas valve but permits operation of the gas valve independently of the foot valve in one direction. Both valves are variable in area, that is, the upper portion 9 of the gas valve is smaller in area than the lower portion !4; conversely, the upper end or the face of the foot valve presents a larger area than the lower portion l2 This is of considerable importance as will hereinafter appear.

In order to further describe the construction and operation of the pump, let it be assumed that it is to be installed in a well which is approximately four thousand (4000) feet in depth, and which has a static fluid level of approximately two thousand (2000) feet. If that is the case, the pump during installation will be lowered to a point where the packer J and pump will assume a position approximately one thousand (1000) feet below the normalstatic fluid level, or in other words, provide a submergence of approximately one thousand (1000) feet.

Under this condition the gas, whereby the pump is actuated, will require a pressure of approximately four hundred (400) pounds, this being sufficient to elevate the oil to the surface, or in other words to cause discharge thereof through the casing head B. In actual operation, let it be assumed that the gas valve is closed and the foot valve open. If that is the case, oil will pass by the foot valve and through the cage and as such will enter the space H] formed around the valve housing and will rise upwardly through the outlet 4 into the discharge column and will continue to rise therein and would rise to approximately one thousand (1000) feet, if it were not for the pressure exerted by the gas on the upper end of the gas valve 9. The static pressure of the oil in the well and in the formation causes the oil to rush in with great velocity when the foot valve first opens, but as the oil continues to rise in the discharge column the velocity gradually slows down and when it has reached approximately seven hundred fifty (750) feet the foot valve will close and the gas valve will open as the pressure of the gas on the upper end of the valve 9 will insure an opening movement. The moment the gas valve opens and the foot valve is closed, gas will discharge under a pressure of approximately four hundred (400) p u d into the annular space !8 and rise upwardly through the outlet and the discharge column and it will form an elongated gas bubble under an approximate pressure of four hundred (400) pounds, which will lift the oil ahead of it in a solid column towards the outlet of the casing head B. The moment, however, that the oil begins to discharge from the casing head, the weight of the oil exerted upon the lifting gas gradually lessens,

and the gas is thus given an opportunity to expand and to lower in pressure and when a pressure of approximately three hundred and fifty (350) pounds is reached the gas valve will close. This is due to the fact that as the gas exerting the lifting force is expanding the formation pressure is increasing, exerting a greater and greater pressure on the lower end of the plunger [4 and on the portion I2 of the foot valve. The area of the extension M, as previously described, is larger than that of the portion 9 of the gas valve; hence the moment the pressure in the well becomes great enough to overcome the pressure of the gas, the gas valve will rise and close off the ports 8, thereby shutting off the gas flow to the discharge column and permitting the gas in the column to expand.

It was previously stated that the area at the.

upper end of the foot valve is greater than at the lower end, hence it is possible for the gas in the discharge column to expand to a considerable extent before the pressure in the formation will be able to lift the foot valve. By properly proportioning, the upper and lower areas of the foot valves, it is possible that the gas in the discharge column may expand down to as low as two hundred (200) pounds before the pressure in the well becomes great enough to open the foot valve. However, when this point is reached the foot valve will rise and the flow of oil from the well into the discharge column will again take place and it will continue until its velocity and pressure decrease to a point where the pressure of the gas on the upper end of the valve 9 becomes suflicient to close both of the valves and when this happens gas will again enter through the ports 8 and the second volume of oil admitted will begin to rise.

By arranging the valves as shown, it will be apparent that the gas flow into the discharge column may be cut off long before the foot valve opens; this being possible because of the independent movement of the gas valve with relation to the foot valve in an upward direction, and it is by this arrangement and construction that it becomes possible to utilize the expanding force of the gas and it is also by this arrangement that the quantity of gas actually employed is reduced.

Again, in view of the fact that the velocity of the oil through the foot valve is high during the first portion of the period of admission and gradually slows up as the static level is approached, it is important to close the foot valve prior to the oil reaching the static level as this considerably shortens the time of each cycle. In some wells actual experience has shown that twelve or more pumping operations are obtained per hour. If the oil was permitted to flow until it reached a static level, the number of pumping operations might be reduced to as little as eight per hour and as such would materially decrease the capacity of the pump. By opening the gas valve and simultaneously closing the foot valve before the static level is reached the number of pumping operations per hour can be materially increased and thereby the capacity of the pump.

The advantages obtained by this pump are as follows:

(1) The only moving parts employed are the two valves, to wit, the gas valve and the foot valve and as their operation is entirely automatic and controlled alternately by gas pressure and liquid pressure, a simple construction becomes possible and auxiliary mechanically actuated mechanism is entirely eliminated;

(2) By the valve arrangement and by the use of the packer J increased oil production is obtained by elimination of the back pressure on the formation, thereby giving more freedom for the entry of the oil into the well;

(3) The gas-oil ratio is very materially reduced, as the actual quantity of gas employed is reduced and the expansive force of the gas is fully utilized;

(4) Inasmuch as the gas enters and functions as a piston to lift the oil aeration of the oil in the discharge column is eliminated and, where water is associated with the oil, emulsion of oil and water is eliminated;

(5) A pump of this character tends to steady production as the gas entering is automatically controlled by the pump and this, in turn, by the pressure of the actuating gas and the pressure in the formation.

(6) A pump of this character materially decreases the lifting cost of the oil. This is effected by group well pumping with pumps of this character and as such eliminates the endless trouble and expense incidental to the sucker-rod method of pumping;

('7) The pump is only limited to the capacity of the well itself. In other words, it will produce all the liquid the well will make, therefore the production is not limited by the capacity of the equipment as is the case with piston actuated P p (8) A pumping system of this character will increase the ultimate yield of oil Wells and by employing a gas anchor of suitable length, as indicated at 22, to suit the conditions of the particular well the production can be taken from a great depth in the fluid column of the well, thereby retaining the gas in the formation which will result in prolonging the life of the well and insuring a higher ultimate yield.

While the pump has been particularly described for operation in oil wells, it is obvious that it is equally applicable to water wells, the only difference being that compressed air will be employed in place of gas. Where gas is employed in oil wells, it will be understood that it may be supplied from any suitable source and, if the pressure is not sufficiently high for the particular well to be operated, a compressor will be installed in the line and will deliver the gas at the proper pressure to the casing around through either of the pipes E or F, and while this and other features have been more or less specifically described, I wish it understood that various changes may be resorted to within the scope of the appended claims. Similarly, that the material and finish of the several parts employed may be such as the manufacturer may decide, or varying conditions or uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:-

l. A gas pressure actuated pump for wells comprising a pump casing adapted to be submerged in the liquid of the well, said casing having an inlet for admission of the liquid and a discharge opening for the liquid, a discharge column connected therewith. a foot valve in the casing between the inlet and the discharge, said valve being actuated by liquid pressure to open, and a gas admission valve for admitting gas under pressure between the foot valve and the discharge column, said valve being operable independently of the foot valve and extending through said valve to be closed by the liquid pressure in the well and opened by the gas pressure.

2. A gas pressure actuated pump for wells comprising a pump casing adapted to be submerged in the liquid of the well, said casing having an inlet for admission of the liquid and a discharge opening for the liquid, a discharge column connected therewith, a foot valve in the casing between the inlet and the discharge, said valve being actuated by liquid pressure to open, a gas admission valve for admitting gas under pressure between the foot valve and the discharge column, said valve'being operable independently of the foot valve and extending through said valve to be closed by the liquid pressure in the well and opened by the gas pressure, and a connection between the gas and the foot valve whereby opening movement of the gas valve is transmitted to close the foot valve.

3. A gas pressure actuated pump for wells comprising a pump casing adapted to be submerged in the liquid of the well, said casing having an inlet for admission of the liquid and a discharge opening for the liquid, a discharge column con-' nected therewith, a foot valve in the casing between the inlet and the discharge, said valve be ing actuated by liquid pressure to open, a gas admission valve for admitting gas under pressure between the foot valve and the discharge column, said valve being 'operable independently of the foot valve and being closed by the liquid pressure in the well and opened by the gas pressure, and

a connection between the gas and the foot valve whereby opening movement of the gas valve is transmitted to close the foot valve, said gas valve being free to close without opening the foot valve.

4. In a pump of the character described, a cylindricabshaped elongated casing, having inlet and discharge openings formed at opposite ends, a valve housing within the casing having gas inlet and discharge openings formed therein, a valve cage with a seat formed at the lower end of the valve housing, a foot valve guided by the cage and supported by the seat, and a gas controlling valve extending through the foot valve and cage and into the valve housing and adapted to open and close the gas discharge ports, said 1 valve being movable independently of the foot valve to close the gas discharge ports when the foot valve is closed.

5. In a pump of the character described, a cylindrical-shaped elongated casing, having inlet and discharge openings formed at opposite ends, a valve housing within the casing having gas inlet and discharge openings formed therein, a valve cage with a seat formed at the lower end of the valve housing, a foot valve guided by the cage and supported by the seat, a gas controlling valve extending through the foot valve and cage and into the valve housing and adapted to open and close the gas discharge ports, said valve being movable independently of the foot valve to close the gas discharge ports when the foot valve is closed, and means on the gas controlling valve for engaging and closing the foot valve when moving to open the gas discharge ports.

6. In a pump of the character described, a cylindrical-shaped elongated casing, having inlet and discharge openings formed at opposite ends, a valve housing within the casing having gas inlet and discharge openings formed therein, a

valve cage with a seat formed at the lower end of the valve housing, a foot valve guided by the cage and supported by the seat, and a gas controlling valve extending through the foot valve and cage into the valve housing and adapted to open and close the gas discharge ports, said valve being movable independently of the foot valve to close the gas discharge ports when the foot valve is closed, said gas controlling valve being a differential area valve with the smallest area exposed to the gas inlet and the largest area extending through the foot valve and being exposed to the pressure of the liquid to be pumped.

7. In a pump of the character described, a cylindrical-shaped elongated casing, having inlet and discharge openings formed at opposite ends, a valve housing within the casing having gas inlet and discharge openings formed therein, a valve cage with a seat formed at the lower end of the valve housing, a foot valve guided by the cage and supported by the seat, a gas controlling valve extending through the foot valve and cage and into the valve housing and adapted to open and close the gas discharge ports, said valve being movable independently of the foot valve to close the gas discharge ports when the foot valve is closed, said foot valve being a variable area valve having its smallest area exposed to the pressure of the liquid to be pumped and its largest area to the liquid to be lifted.

8. In a pump of the character described, a cylindrical-shaped elongated casing, having inlet and discharge openings formed at opposite ends, a valve housing within the casing having gas inlet and discharge openings formed therein, a valve cage with a seat formed at the lower end of the valve housing, a, foot valve guided by the cage and supported by the seat, and a gas controlling valve extending through the foot valve and cage into the valve housing and adapted to open and close the gas discharge ports, said valve being movable independently of the foot valve to close the gas discharge ports when the foot valve is closed, said gas controlling valve being a differential area valve with the smallest area exposed to the gas inlet and the largest area extending through the foot valve and being exposed to the pressure of the liquid to be pumped, said foot valve being a variable area valve having its smallest area exposed to the pressure of the liquid to be pumped and its largest area to the liquid to be lifted.

WILLIAM W. THAYER. 

